Mashable has the details...

The honor is reserved for a top-tier donator on Martin's Prizeo crowdfunding campaign, raising money to support the Wild Spirit Wolf Sanctuary and Food Depot in Martin's adopted hometown of Santa Fe, New Mexico. The winner will choose their character's position in the fictional world (lordling, maester, peasant, whore, etc.) and meet a grisly death that could rival the Red Wedding.

The Hollywood Reporter explains why...

Martin and his wife, Parris McBride, are avowed wolf lovers and say the money will go toward improving the habitats at the Wild Spirit Wolf Sanctuary. It will also benefit a local food pantry, The Food Depot of Santa Fe.

Nerdist has their doubts...

Listen, we’re not complaining — by any stretch — we want to stay in Westeros as long as possible. But considering how long it takes him to write each mind-bogglingly long novel, in addition to the pressures of the television series catching up, is an eighth book really such a good idea? Is it even feasible?

WochitEntertainment: You Could Be A Character In Game Of Thrones

The only thing better than Game of Thrones is being in Game of Thrones. Using Prizeo, Game of Thrones author George R.R. Martin is trading away tons of GoT-themed prizes to help out with some of the causes he's most passionate about, wolves and ending hunger. For a cool $20,000 , Martin will name a character after you, let you choose that character's station in life, and brutally murder that character in a manner befitting one of the most gruesome, blood-lustful series ever.